REFLEX MOTOR OUTPUT TO TORQUE PULSES IN MAN - IDENTIFICATION OF SHORT-LATENCY AND LONG-LATENCY LOOPS WITH INDIVIDUAL FEEDBACK PARAMETERS

Pseudo-random torque disturbances were applied to the human forearm to characterize the relations between the reflex motor output and the kinematic variables using a linear model. The best least-squares fit to the model relating average electromyographic activity to forearm angular position, velocity and acceleration was obtained by assuming separate time delays for each kinematic variable. Best estimates for the time delays were 86 ms for position, 25 ms for velocity and 45 ms for acceleration. The central structures which could be primarily involved in mediating the velocity and acceleration feedbacks are discussed. © 1979.